Dual-flow discharge nozzles may be utilized under circumstances where two separate, independent flow paths are to be provided for the discharge of fluids which are to be maintained isolated from each other to the point of discharge. The fluids may be liquids or gases or a liquid and a gas or perhaps even a fine powder. In other cirscumstances, the dual-path discharge nozzle may be used to discharge a liquid from one port and to draw off through a second port, the volatile vapors formed by the discharge of the liquid. For example, in dispensing gasoline for automobiles at service stations, the hazards resulting from the formation of gasoline fumes can be considerably reduced and minimized by use of such a dual-path nozzle which will draw off the gasoline vapors from the tank of the vehicle at the same time that the tank is being filled with the liquid gasoline through another port of the nozzle. To accomplish this, two flexible hoses have to be connected to the nozzle; one for carrying the liquid gasoline for discharge by the nozzle, and the second for providing a suction to withdraw the fumes.
As is well known, the nozzles used in gasoline service stations must be capable of rotation or swiveling to accomodate to the various angles and positions which are required in filling the fuel tanks of vehicles. Unless some swivel connector or coupling is provided between the nozzle and the supply hose, the nozzle cannot be freely manipulated or, if manipulated, can cause kinking and damage to the supply hose. It is customary to provide such a swivel coupling between a single supply hose and the conventional discharge nozzle employed in service stations.
With the advent and increased use of the dual-flow nozzle in service stations and the necessity for connecting two hoses to the nozzle instead of the conventional single hose, the problem of preventing kinking, snarling and twisting of the hoses has become more complex and has been attempted to be solved by utilizing a conventional swivel coupling to connect the nozzle to at least one of the hoses in order to obtain at least some curtailed degree of swivel action with respect to one of the hoses. Preferably, two of such conventional swivel couplings are utilized between the nozzle and the two respective hoses so that each hose is permitted some swivel action relatively to its attachment to the nozzle, but this arrangement still does not eliminate the twisting and kinking of the hoses around and relative to each other as the nozzle is manipulated.